Question

which is true of all organisms in the phylum chordata? they have legs with digits or fingers. they all have a dorsal, hollow nerve cord. they all do not have vertebrae. they all have scales.

Explanation:

To determine the correct statement about all organisms in Phylum Chordata, we analyze each option:

• Option 1: Not all chordates have legs with digits (e.g., fish, snakes). Eliminate.
• Option 2: A dorsal, hollow nerve cord is one of the four key chordate characteristics (present at some stage). This is universal.
• Option 3: Most chordates (vertebrates) have vertebrae; some (like lancelets) don't, but the statement "all do not have" is false. Eliminate.
• Option 4: Not all chordates have scales (e.g., mammals, birds). Eliminate.

Answer:

B. They all have a dorsal, hollow nerve cord.